AC High Pressure switch

[KenC]

Is the pressure switch that goes into the receiver/dryer the same on all e30 AC systems?

[ian332isport]

Is the pressure switch that goes into the receiver/dryer the same on all e30 AC systems?

Ken,

Early systems (r12) used a pair of switches (high and low pressure). Later (r134a) systems used a single combined switch. As far as I'm aware that's the only difference.

If you buy an r134a retrofit kit from BMW it comes with the single combined switch and describes how to connect it up etc.

Cheers,

Ian.

[KenC]

I have an r12 system. Where is the low pressure switch? I only see one going into my receiver/dryer.

[ian332isport]

I have an r12 system. Where is the low pressure switch? I only see one going into my receiver/dryer.

I assume you have the later receiver/dryer with the single switch. This is compatible with both r12 & r134a.

If you look at the wiring down by the receiver/dryer, you will probably see the wires for one of the original switches shorted together.

Cheers,

Ian.